Protective headgear and helmets have wide uses. Multiple liners are used for comfort and protection. To assemble a multi-liner helmet, the liners are glued or otherwise permanently fixed together into a rigid form. Because a rigid helmet body does not address rotational impacts, an additional liner may be included for the purpose of addressing such impacts. As a result, the volume of the helmet body is generally increased. Components of the helmet also often need to be attached to the helmet body. The liners are not readily provided with external attachment for parts. The attachment couplings for external parts can be in-molded in the liner, but it is difficult due to manufacturing constraints. Addition of attachment locations for parts also increases the number of parts needed for assembling a helmet.